PART IV. Die Errors:

Collar Cuds: 

Retained Collar Cud

With this type of collar break, part of the collar breaks off but does not fall away. Instead,  it remains close to the intact part of the collar. It may be that the hardened working face of the collar breaks off and sinks into the surrounding softer metal.  Or it may be that one side of the collar breaks away but is held in place by bolts or clamps or whatever anchors the collar to the press frame.

Although it’s sometimes difficult to distinguish from a bilateral split collar, there are some telltale diagnostics. A bilateral split collar shows only horizontal spread. This creates a raised nib at both poles (see bilateral split collar),
but the curved outline of the coin is largely undisturbed except for the fact that the original circle is converted to a modest oval. With a retained collar break you look for evidence of vertical movement, horizontal offset, or pivoting – something that indicates unusual mobility in part of the collar. Diagnostics to look for are as follows:

1. Evidence of collar contact on both sides of the break at one or both endpoints. Collar contact will be seen along most of the edge that lay adjacent to the mobile side of the collar.
2. A step-up at one endpoint and a step-down at the other endpoint. This may indicate a pivoting movement of the detached portion of the collar or it could mean the presence of horizontal offset (a sliding movement in the direction of one endpoint). Both patterns of movement can of course be present.
3. A partial collar “step” that occupies a different height on either side of the break. This indicates vertical movement.
4. A partial collar that slopes down (or up) on one side of the break at a different angle from the other side of the break. This indicates the presence of tilt on the loose half of the collar

Depicted below is a 1973-D cent with a retained collar break on the right side. With diagnostics 1 and 2 present the endpoints are 180 degrees apart and can be seen at 1:00 and 7:00. There is clear evidence of collar contact on either side of the break at the upper endpoint, and clear evidence of collar contact along much of edge along the right side. There is a step-up at 1:00 and a step-down at the 7:00. It’s probably indicative of horizontal offset since expansion on the right side is symmetrical. Pivoting is associated with uneven expansion that’s greater toward one endpoint. A collar chip lies along the right side of the break at the 1:00 position. It extends from one rim to the other.